Once the antenna was built, the Vector Network Analyzer was used to send microwaves through the antenna to receive data. The network analyzer transmits microwaves at different frequencies all with the same power resembling a box function. A box function transformed into the time domain is a sinc function. The sinc function has an initial pulse and then it trails off to zero. This trail after the pulse creates noise in the signal and makes any reflections received difficult to identify.
To receive just a short pulse in the time domain a differentiated gaussian function is used.
The time signal used to receive a short pulse was developed by Dr. Elise Fear. This signal will return a differentiated gaussian signal at a center frequency of 4 GHz.
However, due to the antenna a signal at a high frequency is preferred. The signal must be working with a center frequency of around 10 GHz for the antenna to perform correctly. A picture of the 4 GHz and the 10 GHz signals are shown below:
From the results above the data received from the network analyzer must be multiplied by the weighting function. This will transform the box function into a differentiated gaussian function. However, the differentiated gaussian function see above will not weight all the data symmetrically. Therefore, a hamming window, shown in red, will be multiplied by the second half of the original signal to receive a symmetrical gaussian function, shown in purple.
The data will eventually have to be transformed into the time domain. Therefore, certain conditions must be met as to receive the proper signal in the time domain. The first step is to make the data into a complete spectrum from 25 GHz to 25 GHz. The second step is to complex conjugate the negative frequency. These properties are from the Fourier transform property V(f) = V*(f). The signal is then transformed to the time domain and it resembles the signal shown below.
